4 speed ka-booom !

Well on the good side I won my very first - first round elimination! :burnout:
going for round two -do burnout, rev up and it jumped a little bit and then a terrible grinding. I thought it slipped out of gear so i jam it forward and it grinds again. So I tried second and grind. so i tried reverse - it worked but sounded grumbly.
So I empty oil and it's clean with lots of metal particles. Pulled gear box and opened up the side cover expecting to see mayhem and all I see is one small chipped tooth on what I believe to be first gear?
Is there something else that I'm not seeing ? ?
Thank you....